JBO Thread Plug Gauge - Metric Fine Go/No-Go - Right Hand - 6H - M39 x 0.75 Boring Bar Blank The sealed design minimizes coolant

The sealed design minimizes coolant mess

This reamer is engineered for dependable

Ground: Hollow-ground to bore for side clearance

The M2 HSS material holds its edge well for repeated use

The two-flute geometry strikes a balance between rigidity and efficient material removal

JBO Thread Plug Gauge - Metric Fine Go/No-Go - Right Hand - 6H - M39 x 0.75 Boring Bar Blank The sealed design minimizes coolantThe JBO Thread Plug Gauge is a precision inspection tool designed for metric fine threads. Specifically crafted for M39 x 0. 75 applications, this right hand, Go No Go gauge helps shops verify threaded holes quickly and reliably. Its ideal for machinists, assembly lines, and QA teams that need fast, accurate fits without guesswork. Made from hardened steel for exceptional durability, this plug gauge resists wear and maintains accurate measurements